Based on the original design by Mark Tilden for use in the B.I.O.Bugs & RoboSapien, these motors are the next generation with a variety of improvements such as dual output shafts and a lower current motor.

Check out this quick tutorial for how to modify the GM2 from a torquey slow 224:1 ratio to a speedy 14:1 ratio.

Do you need to mount something to the shaft of the motor? Try the GMW - it's a very effective platform for a variety uses. Alternatively, you'll also find that a #2x1/4" SMS screw will provide a snug fit for your need.